There are snap rings known and widely in use which have relatively to each other substantially eccentric inner and outer faces and a gap for enabling them to be radially deformed in a limited extent and to fasten them onto parts of a slightly smaller or bigger diameter respectively whereafter the difference of the respective face of the snap ring and the part provides, that the snap ring keeps itself on the part or in a groove of the part.
Those known snap rings are however keeping the part only partially enclosed because the gap of the snap ring is open relatively to the to be spanned part.
Therefore the disadvantage of the known snap rings is that they can radially surround only a portion of the respective part whereto the snap ring is fastened and that, when for example the part is itself o deformable materiel like plastic, gum or like or of soft metall, it may deform into the gap of the snap ring whereby an undesired opening might appear.
The common snap ring is therefore for example unsuitable to fasten a plastic hose around a pipe, because fluid in the pipe might escape through said gap.
It is therefore an object of this invention to overcome the disadvantages of the known snap rings.
Another object of the invention is to strengthen the radial fastening capability of the snap ring. A still further object of the invention is to provide a snap ring with an uninterrupted inner face or outer face by setting four snap rings together axially behind each other with two inner and two outer rings whereby the directions of the gaps are differently directed, so, that the inner rings are closing the radial gaps of the outer rings and vice versa.
Further, more detailed objects of the invention are, to provide .alpha. snap ring consisting of four substantially equal plane rings, wherein each ring has an inner face and an outer face with an eccentricity between said faces for forming a radially wider portion on the respective ring and a radially narrower portion on the respective ring, wherein said radially wider portion bears the main force of the radial capability to spann said ring in radial direction,
wherein a slot is provided cutting said radially narrower portion for making a radial flexibility of said ring possible,
wherein an imaginary face can be assumed through the middle of said wider and narrower portions, whereby said ring forms portions of symmetry around said imaginary face;
wherein said slot extends normal or under an angle relatively to said imaginary face,
wherein an extension of one arm of said ring extends along said slot to form the other wall of said slot,
wherein the other arm of said ring ends on said slot
wherein said ring includes at least one connection portion for fastening of a plurality of rings axially behind each other,
wherein said four rings consist of two inner rings and of two outer rings, wherein said inner rings are axially behind each other,
wherein one of said outer rings attaches one of said inner rings and the other outer ring attaches the other of said inner rings,
wherein said inner rings are oppositionally mounted respectively to said outer rings whereby said extensions of said inner rings face said slots of said outer rings,
wherein said arm extensions extend radially beyond said slot; and
wherein said rings are axially behind each other are kept together by connection means to form together said snap ring, whereby the inner rings are closing the slot areas of said outer rings and said outer rings are closing the slot areas of said inner rings for forming a radially allround inner face set on said snap ring while said snap ring may be radially expanded by pressing said extensions together by a respective pair of forceps for moving said snap ring over a cylindrical part to be fastened whereafter when said extensions are released from said pair of forceps, the said snap ring clamps radially inwardly to keep said part kept allround spanned by said inner faces of said rings under the radially inwardly directed spanning forces of said snap ring, and:
.alpha. snap ring consisting of four substantially equal plane rings, wherein each of said rings has an inner face and an outer face with an eccentricity between said faces for forming a radially wider portion on the respective ring and a radially narrower portion on the respective ring, whereby said radially wider portion bears the main force of radial capability to spann said ring in radial direction, wherein a slot is provided, cutting said narrower portion for making for making a radial flexibility of said ring possible,
wherein an imaginary face can be assumed through the middles of said wider and narrower portions, whereby said ring forms portions of symmetry around said imaginary face,
wherein said slot extends normal or under an angle relatively to said imaginary face,
wherein an extension of one arm of said ring extends along said slot to form the other wall of said slot,
wherein the other arm of said ring ends on said slot to form the first wall of said slot,
wherein said ring includes at least one connection portion for fastening of plural rings axially behind each other around a common axis, wherein said four rings consist of two inner rings and two outer rings, wherein said inner ring are axially behind each other, wherein one of said outer rings attaches one of the inner rings and the other of said outer rings attaches the other of said inner rings,
wherein said inner rings are oppositionally mounted respectively to said outer rings whereby said extensions of said inner rings face said slots of said outer rings,
wherein said outer faces of said rings can be retracted radially inwardly by narrowing said slots,
wherein said outer faces expand radially when the retraction is released, and
wherein said outer faces are forming a common allround outer face able to fasten itself under the own radial expansion force within a hollow cylinder whereby the respective portions of the said inner rings are facing the slots of said outer rings and respective portions of said outer rings are facing the slots of said inner rings.
The specifities of the snap rings or of the snap ring assemblies of the invention may be defined in the shortest possible description as follows:
A snap ring of partially symmetric configuration about an imaginatory medial face through centric and an eccentric axes,
wherein one radius around one of said axes defines at least a portion of an outer face of said snap ring,
wherein another radius around the other of said axes defines at least a portion of an inner face of said snap ring, and
wherein a gap slots said snap ring radially while said gap is distanced from said imaginary medial face and set in an angle relatively to said medial face.
In an alternative means are provided on said ring to give hold for a spanner to radially deform said ring against the radial forces of said ring.
The centric inner faces of outer faces of the rings may also be tapered with respect to their axes in order to cut into the bar or hollow body whereon they are set in order to obtain a specially strong capability to hold against thrust in axial direction.